Electrical and Optical Properties of Cu2Zn(Fe,Mn)SnS4 Films Prepared by Spray Pyrolysis

Abstract

We have analyzed the electrical and optical properties of Cu₂ZnSnS₄, Cu₂FeSnS₄, and Cu₂MnSnS₄ films with the p-type electrical conductivity, which were prepared by spray pyrolysis at temperature TS = 290°C using 0.1 M aqueous solutions of salts CuCl₂ · 2H₂O, ZnCl₂ · 2H₂O, MnCl₂ · 2H₂O, FeCl₃ · 6H₂O, SnCl₄ · 5H₂O, and (NH₂)CS. The energy parameters have been determined from analyzing the electrophysical properties of the films using the model of energy barriers at grain boundaries in polycrystalline materials, and the thickness of intercrystallite boundaries has been estimated. The extent of the influence of the hole concentration p₀ in the bulk of crystallites and height E_b of the energy barriers between grains on the electrical conductivity has been determined. The optical bandgap width for thin Cu₂Zn(Fe,Mn)SnS₄ films has been calculated based on analyzing the spectral dependences of the absorption coefficient.